Irrigation systems have been used for many years to provide plants and trees with water at various times during their growing cycle. For example, it has been common practice to provide plants and trees with water by means of irrigation ditches, hoses, sprayers, pipes and other types of apparatus. However, in certain situations such as in orchards where the terrain is uneven, water will run from the high ground to the low. In such cases, the low lying trees may receive more water than those on higher ground.
In other cases where the cost of water is relatively high it is desirable to control the amount of water provided for each area and to avoid wasting water by providing additional water to some plants in order to adequately water others leaving the water on for too long a period.
The above problems have been overcome to a degree by irrigation systems having a plurality of valves with each valve connected by means of pipes to a pressurized source of water. Such systems are disclosed in my earlier U.S. Pat. No. 5,213,130 entitled "Irrigation System" and which is incorporated herein in its entirety by reference. As disclosed therein, an irrigation system includes one or more valve assemblies which are connected in series to a pressurized source of water. Each valve assembly includes a cylindrical housing, a ball valve, an inlet and two outlets with one outlet generally opposite from the inlet in a lower portion of the housing. The other outlet is disposed in an upper portion of the housing and is adapted to direct water to an area of ground for irrigation. A pit and a float are associated with each valve assembly and arranged so that some of the irrigation water will flow into the pit and raise the float. The float is connected to spring biasing means and when the float reaches a predetermined level the ball valve will spring upwardly to close the upper outlet and redirect the water to another assembly. Water pressure will then maintain the valve in that position until it is manually reset.
A further development for an improved system of the aforementioned type is disclosed in another of my U.S. Pat. No. 5,174,499. In the system disclosed therein, the amount of water to be delivered to a given area is independent of any changes in water pressure. For example, an irrigation system in accordance with that invention includes means for storing a force such as a compression spring which is sufficient to overcome a force against the ball-shaped gate member due to the flow of water. Therefore, when the float reaches a predetermined height, the force in the spring is released to thereby direct the flow of water through the second outlet. In such systems, the opening of one outlet and closure of a second is solely dependent on the position of the float, i.e. the water level within a pit.
A more recent development in flow controlled irrigation systems is disclosed in my U.S. Pat. No. 5,176,163 entitled "Flow Controlled Irrigation System". As disclosed therein, a flow controlled irrigation system automatically stops the flow of water to an area when that area has received a predetermined quantity of water and then redirects the water to another area. The system includes an upwardly extending gate member which defines a pair of passages therein. A first of the passages directs water to an area to be irrigated while the second causes the water flow to bypass the area. A flow control member activates the gate member when a predetermined volume of water flows through a meter.
It is now believed that there is a significant commercial market for an improved device for use in systems such as those disclosed in my earlier patents. Such devices allow an individual to preselect a quantity of water to be supplied to a given area and to activate the mechanism automatically when the quantity of water passes through a valve. The improved irrigation devices in accordance with the present invention also offers a number of advantages over my earlier disclosed devices. For example, such systems include pressure release means which facilitate redirecting the flow of water from one area to another, are durable, minimize damage due to abuses in resetting the valve, require less force to reset the valve and minimizes the likelihood of a valve sticking due to the pressure from the water flow.